This invention relates to vibrating screens and more particularly to variably sloped vibrating screens.
The aggregate industry utilizes many styles of screen machines to sort aggregates by size. Most screen machines utilize vibration to agitate the mixture of aggregates to promote separation through various sized openings in the screening surfaces. Sorting is achieved by undersized particles passing through the openings in the screening surface and the oversized particles being retained above the screen surface. These machines usually have some type of vibrating mechanism to shake the unit and its screening surfaces. The vibrating mechanisms usually include an unbalanced weight mounted on one or several rotating shafts which when rotated, force a cycling motion into the screen machine.
These screen machines are normally operated in a single orientation which may be either horizontal or inclined.
Fixed inclined screens are constructed so the screen surfaces are sloped, usually toward the discharge end, to aid material movement to the end and off the screen.
Sometimes a screen is designed to be operated in various sloped positions. This is frequently found in portable equipment that also requires a lower profile for travel, as well as multiple sloped positions as needed for various screening applications.
In the past, mobile variable sloped track screens have provided for the ability to adjust operating angle by including structure such as nested tubes with holes extending through both tubes and a pin which is inserted through four holes in the two tubes.
While these systems have provided for variable positions, they did have several drawbacks, for example, it is difficult to gain alignment of the 4 holes and insert the pin in a quick and certain manner. Alternately, the holes could be made larger, thereby making alignment easier; however, the slack in the system can result in excessive vibration in certain circumstances. Consequently, there is a need for improvement in lift and support systems for vibrating screens.